The hantavirus Andres strain has now become an international concern following a cruise ship outbreak.
The Andes strain of hantavirus stands out as the only known variant capable of human-to-human transmission. Most strains that spread solely through rodent bites or scratches, as well as direct contact with contaminated material, CNN reported.
Dr Maria Van Kerhove, WHO's Director for Epidemic and Pandemic Preparedness and Prevention, said it's safe to assume that's what happened with the MV Hondius outbreak, after symptoms of the illness were observed in at least two passengers and two crew members.
What Caused the MV Hondious Hantavirus Outbreak?
'We do know that some of the cases had very close contact with each other and certainly human-to-human transmission can't be ruled out so as a precaution this is what we are assuming,' Kerhove stated.
After departing Ushuaia, Argentina on 1 April, the MV Hondius cruise ship remains stranded at Praia, Cape Verde as of 3 May with no authorisation to dock at port. One victim died onboard on 11 April, another on 2 May. Another casualty died in South Africa on 26 April, shortly after leaving the ship.
The World Health Organisation reported seven cases as of 4 May, including two laboratory-confirmed hantavirus infections, five suspected, three deaths, one critically ill patient, and three with mild symptoms.
Hantavirus Symptoms Observed in MV Hondius Cruise Ship
The symptoms observed from 6 to 28 April include fever, gastrointestinal symptoms, rapid pneumonia progression, acute respiratory distress syndrome, and shock.
The ship, now anchored off Cape Verde, saw three passengers evacuated, two seriously ill, with one in intensive care in South Africa and another currently admitted at a medical facility in Zurich.
Authorities are now scrambling with contact tracing as countries coordinate case isolation, medical evacuations, and laboratory investigations. The WHO assesses the wider public health threat as low despite the origin and nature of the outbreak.
How Does the Hantavirus Infection Spread?
Hantaviruses generally infect humans via contact with infected rodents' urine, droppings, or saliva, often inhaled as contaminated particles in enclosed spaces.
Bites or scratches from rodents represent rare additional routes, while contaminated surfaces touched then followed by mouth or nose contact can also transmit the virus.
The Andes virus typically circulates in Argentina and Chile, with documented human-to-human cases in family clusters where close household contact increases risk.
Transmissions occur during the prodromal phase, potentially airborne, as seen in a 2018 outbreak in Epuyén, a village in Argentina's Chubut province.
In the Americas, hantaviruses like Andes cause hantavirus cardiopulmonary syndrome with up to 50% fatality. Globally, WHO estimates 10,000 to 100,000 annual infections in humans with varying severity.
Past reports of cases in China, Paraguay, Chile, Panama, and the US found no conclusive evidence of human-to-human transmission, with most of the infections originating in rural areas.
Most of the MV Hondius' reported 150 passengers remain onboard, some have already disembarked, including Americans. The Georgia Department of Public Health is currently monitoring two residents who are 'currently in good health and show no signs of infection,' the New York Times reported.
